Electricity

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A natural gas power plant in Long Beach that uses "once-through" cooling.

We hear a lot about how green our energy is in California. Instead of using coal, the state runs on natural gas and increasingly, renewable power.

But there’s a hidden cost to our energy supply: water use. In fact, every time you turn on a light, it’s like turning on your faucet. It’s been calculated that it takes 1.5 gallons of water to run a 100-watt light bulb for 10 hours.

The way water and power work together is a lot like a tea kettle. Steam drives the power industry.

How Power Needs Water

You can see it at the Gateway Generating Station, a natural gas power plant in the northeast Bay Area. The plant looks complicated but making power is pretty simple. Step number one: burn natural gas. That produces a lot of heat.

“You’ve got 1,700-degree exhaust energy, or waste heat,” says Steve Royall of PG&E, who is giving me a tour through the maze of pipes and compartments. The heat hits pipes that are filled with water and the water is boiled off to create steam. That’s step number two: make steam to turn a steam turbine, which is attached to a generator. It’s the water that’s making the power.

State rebates could offset electrical sticker shock, finds a new study

Forcing utilities to pay for their carbon emissions, as California plans to do, will mean more costly megawatts. Six months before formal compliance with the state’s new cap & trade system begins, regulators are still sorting out what to do about that.

One of them is to provide rebates to offset hikes in electric bills. A new report from the clean-economy advocates, Next 10 attempts to sort out the options and put some concrete numbers on them. For example, the authors estimate that for PG&E customers, pricing carbon will add somewhere from two-to-seven dollars a month to summer electric bills, and anywhere from $2.50-to-more than $10 for customers served by Southern California Edison. Where you fall in that range depends in part on which of California’s many climate zones you live in. Places like the Inland Empire, which rely more on air conditioning, would fall in the upper end of the range. Continue reading →

Solar-thermal plants use mirrors or "heliostats" to focus sunlight on a tower receptor that produces steam to generate electricity.

A major barrier for solar power has always been that it doesn’t work at night (Duh). A few years ago, developers of big “utility-scale” solar projects were able to shrug this off to some degree. But Oakland-based BrightSource Energy has reversed field and decided to add to several projects the ability to store electricity for distribution after dark.

BrightSource managers say times have changed. Where utilities once wanted all the renewable capacity they could get, to meet state requirements, the priority has since shifted to having those renewable electrons available when they’re needed.

“The challenges of integrating photovoltaics and wind into the grid have driven a much deeper appreciation for those that can be highly reliable,” BrightSource CEO John Woolard told me in a phone interview. Continue reading →

A new study suggests that massive electrification will be required to meet California's 2050 goal for greenhouse has reductions.

Chances are you’ve at least heard about California’s legal requirement to wind back greenhouse gas emissions to 1990 levels by 2020. But the state has a longer-term goal to knock another 80% off that by 2050. Is that even possible?

A new study suggests that it is — but not without a wholesale transformation from an “oil economy” to an “electric economy.”

The study, a collaboration of economists and energy forecasters at several institutions, including Lawrence Berkeley National Lab, three fundamental resets will be required to make that goal: Continue reading →

US power plants are “stressing” freshwater supplies, finds science watchdog group

A UCS study says US power plants are sucking up three times the volume of water that goes over Niagara Falls on a daily basis.

For the second time in as many weeks, a major report has emerged warning of consequences from the demand that America’s electricity producers are placing on water supplies.

Today’s findings, from the Union of Concerned Scientists, conclude that water and power are on a collision course in the US, as nearly all major power plants slurp up water for cooling. As of 2008, the UCS study found that across the US, “thermocooled” power plants (which is most of them) took up somewhere between 60 billion and 170 billion gallons of water from rivers, lakes and aquifers. That’s three times the volume of water that pours over Niagara Falls. At least 2.8 billion and as much as 5.9 billion gallons of that was “consumed,” or not put back.

Power Plants are putting strain on watersheds throughout the nation, according to UCS researchers.

“It’s really water that keeps the lights on,” says Kristen Averyt, deputy director of the Western Water Assessment at the University of Colorado, and lead researcher for the report. Continue reading →

Homeowners and businesses have now installed one gigawatt of roof-top solar panels, according to a report released this week by the advocacy group Environment California.

A gigawatt – or a thousand megawatts – is enough energy for about 600,000 homes. Only five nations — let alone states — including Germany and Japan, have reached that level. “Even in a bad economy, the solar industry has been growing exponentially by 40 percent per year,” says Michelle Kinman of Environment California. Continue reading →

Wind is one of the few energy sources that requires virtually no water.

The Gordian knot of interdependence between water & power (not the political kind — that’s another story) has been getting a lot of attention lately as the “water-energy nexus.” A new report from Oakland’s Pacific Institute warns that as population grows and a changing climate further wrings water out of the West, “These trends will intensify water resource conflicts throughout the region.”

A key component of new solar panel technology being tested at Stanford. (Photo: Nick Melosh)

In a kind of cruel paradox, heat has always been the enemy of solar panels. At higher temperatures, photovoltaic cells become less efficient, which is problematic in an industry where efficiency is the name of the game. That heat also represents wasted energy.

Today, researchers at Stanford University announced that they may have helped solve that problem. Nick Melosh of Stanford’s Materials Science & Engineering department set out to make use of the wasted heat. He and his colleagues created a solar cell technology that uses both light and heat to generate electricity. It’s called “photon-enhanced thermionic emission” (or PETE for short). “This is the first time that a process has been reported that can use the heat and the photons together harmoniously,” says Melosh. Continue reading →

California’s commercial buildings suck up more than a third of all the electricity used in the state–and that’s too much.

That’s among the conclusions of a new report from the San Francisco-based think tank Next 10. The 12-page report points out that on average, such buildings could cut energy use by 30% just by upgrading insulation, and another 18-to-20% with more efficient lighting.

Though California leads the nation in its stingy use of electricity overall, the report notes that efficiency standards for new construction are “well below what is possible” and what standards are in place are not met by 40% of new buildings. Study co-author Tracey Grose says that’s partly because even if state-of-the-art equipment is installed, it isn’t always used as intended. There are no energy efficiency standards at all for existing buildings. In general, the study finds that energy use in most buildings could be cut by 80% with some basic upgrades.

The report, compiled by the consulting firm Collaborative Economics in Mountain View, and largely a compilation of existing work, also implies that there’s a built-in way to pay for some of these improvements. The authors cite studies showing that commercial tenants are willing to pay higher rents for “greener” space. The report also cites figures from the Building Owners & Managers Association, that some basic improvements in energy efficiency offer a three-to-one return on investment.

Power consumption varies widely within the commercial sector. Next 10 notes that restaurants are the biggest kilowatt hogs per square foot, followed by supermarkets and hospitals (when’s the last time you had to wear a sweater while grocery shopping because the frozen food section was chilling the whole store?).

According to the report, while raw consumption has continued to rise, efficiency in these buildings has leveled off in recent years. Overall, the nearly 6.8 million square feet of commercial space accounts for 37% of California’s electricity use, compared with 40% for commercial buildings nationwide. The latter accounts for more than a quarter of the nation’s carbon dioxide emissions, according to the report.

Next 10, which describes itself as an “independent, non-partisan organization” has been a vocal promoter of the economic benefits from greening the state’s economy.

The announcement came after state Senator Dean Florez (D-Shafter) held a press conference in Bakersfield to question why the CPUC hadn’t taken action. Last October, the Commission agreed to quickly hire an independent contractor to test the meters.
Florez got involved in the flap last year after some of his Central Valley constituents saw their bills triple with the new meters, even if customers bought energy saving appliances, or in some cases, when no one was living at the home. “The biggest savings recognized so far has been to PG&E, who were able to lay off numerous meter readers,” said Florez in a press release.

PG&E has blamed the higher bills on rate increases and hot weather (not a new phenomenon in the Central Valley, where people coddle their air conditioners as if they were household pets).

The Bakersfield Californianreported last month that the backlash here in the Central Valley is catching the attention of industry analysts and utilities nationwide, who want to avoid a spreading backlash against the new technology.

One of the groups sounding a warning is the Division of Ratepayer Advocates, an independent consumer advocacy division of the CPUC. Last week, it advised the Commission to reject a Southern California Gas application to fund its own $1 billion smart meter program. DRA argued not that utility bills would spike with new digital meters, but that money could be better spent on energy efficiency measures and appliances. DRA says SoCalGas is overestimating how much customers will reduce their usage if they can see a digital display of how much energy they’re paying for.

Part of the concept behind smart meters is to help utilities with “demand response” strategies; providing timely feedback to customers, who can use their home computers to see exactly how and when they’re using power, customers might then alter their consumption patterns to avoid peak demand periods, and cut utility bills.

But some of that strategy has already backfired. The San Francisco Chroniclerecently reported that a document PG&E filed with the CPUC says the advanced digital smart meters will let the company shut off power to more customers who fall behind on their bills, since they can do so without having to send a crew to a customer’s home. The meters may be smart but consumer advocates say it’s a dumb strategy that will make it easier for the utility giant to leave customers out in the cold.